X60s network problem

[aggy]

We have x60s notebook,it has replaced by warranty motherboard (it has networks issues before),but with new motherboard it also have issues - when working just in LAN it working fine,transferring files and so,but when working in Internet it VERY slowly.
If downloading file speed is decreasing vastly and connection is lost. Also, UUID in bios is empty - all zeros.

Any suitable soft to check network statistics?tcp dump,maybe ?